<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>欢迎使用留言板</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Helvetica Neue', Arial, 'Microsoft YaHei', sans-serif;
        }

        body {
            background: linear-gradient(135deg, #6a11cb 0%, #2575fc 100%);
            color: #fff;
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
            position: relative;
            overflow: hidden;
        }

        /* 背景动画元素 */
        .bg-bubbles {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: 1;
            overflow: hidden;
        }

        .bg-bubbles li {
            position: absolute;
            list-style: none;
            display: block;
            width: 40px;
            height: 40px;
            background-color: rgba(255, 255, 255, 0.15);
            bottom: -160px;
            animation: square 25s infinite;
            transition-timing-function: linear;
            border-radius: 5px;
        }

        .bg-bubbles li:nth-child(1) {
            left: 10%;
            animation-delay: 0s;
        }

        .bg-bubbles li:nth-child(2) {
            left: 20%;
            width: 80px;
            height: 80px;
            animation-delay: 2s;
            animation-duration: 17s;
        }

        .bg-bubbles li:nth-child(3) {
            left: 25%;
            animation-delay: 4s;
        }

        .bg-bubbles li:nth-child(4) {
            left: 40%;
            width: 60px;
            height: 60px;
            animation-duration: 22s;
            background-color: rgba(255, 255, 255, 0.25);
        }

        .bg-bubbles li:nth-child(5) {
            left: 70%;
        }

        .bg-bubbles li:nth-child(6) {
            left: 80%;
            width: 120px;
            height: 120px;
            animation-delay: 3s;
            background-color: rgba(255, 255, 255, 0.2);
        }

        .bg-bubbles li:nth-child(7) {
            left: 32%;
            width: 160px;
            height: 160px;
            animation-delay: 7s;
        }

        .bg-bubbles li:nth-child(8) {
            left: 55%;
            width: 20px;
            height: 20px;
            animation-delay: 15s;
            animation-duration: 40s;
        }

        .bg-bubbles li:nth-child(9) {
            left: 25%;
            width: 10px;
            height: 10px;
            animation-delay: 2s;
            animation-duration: 40s;
            background-color: rgba(255, 255, 255, 0.3);
        }

        .bg-bubbles li:nth-child(10) {
            left: 90%;
            width: 160px;
            height: 160px;
            animation-delay: 11s;
        }

        @keyframes square {
            0% {
                transform: translateY(0) rotate(0deg);
                opacity: 1;
                border-radius: 5px;
            }
            100% {
                transform: translateY(-1000px) rotate(720deg);
                opacity: 0;
                border-radius: 50%;
            }
        }

        .container {
            max-width: 800px;
            text-align: center;
            padding: 40px;
            background: rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            border-radius: 20px;
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
            z-index: 2;
            position: relative;
            animation: fadeIn 1s ease-out;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .logo {
            font-size: 60px;
            margin-bottom: 20px;
            color: #fff;
            text-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
        }

        h1 {
            font-size: 3.5rem;
            margin-bottom: 10px;
            font-weight: 700;
            text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
        }

        .subtitle {
            font-size: 1.5rem;
            margin-bottom: 40px;
            opacity: 0.9;
            font-weight: 300;
        }

        .features {
            display: flex;
            justify-content: space-around;
            flex-wrap: wrap;
            margin: 40px 0;
        }

        .feature {
            flex: 1;
            min-width: 200px;
            margin: 15px;
            padding: 25px 20px;
            background: rgba(255, 255, 255, 0.15);
            border-radius: 15px;
            transition: transform 0.3s, background 0.3s;
        }

        .feature:hover {
            transform: translateY(-10px);
            background: rgba(255, 255, 255, 0.25);
        }

        .feature-icon {
            font-size: 40px;
            margin-bottom: 15px;
        }

        .feature-title {
            font-size: 1.2rem;
            margin-bottom: 10px;
            font-weight: 600;
        }

        .feature-desc {
            font-size: 0.9rem;
            opacity: 0.8;
        }

        .cta-button {
            display: inline-block;
            padding: 18px 50px;
            background: #fff;
            color: #2575fc;
            text-decoration: none;
            border-radius: 50px;
            font-size: 1.3rem;
            font-weight: 600;
            margin-top: 20px;
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
        }

        .cta-button:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 25px rgba(0, 0, 0, 0.3);
            color: #6a11cb;
        }

        .cta-button:active {
            transform: translateY(0);
        }

        .cta-button::after {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            width: 5px;
            height: 5px;
            background: rgba(255, 255, 255, 0.5);
            opacity: 0;
            border-radius: 100%;
            transform: scale(1, 1) translate(-50%);
            transform-origin: 50% 50%;
        }

        .cta-button:focus:not(:active)::after {
            animation: ripple 1s ease-out;
        }

        @keyframes ripple {
            0% {
                transform: scale(0, 0);
                opacity: 0.5;
            }
            100% {
                transform: scale(50, 50);
                opacity: 0;
            }
        }

        .footer {
            margin-top: 50px;
            font-size: 0.9rem;
            opacity: 0.7;
        }

        /* 响应式设计 */
        @media (max-width: 768px) {
            h1 {
                font-size: 2.5rem;
            }

            .subtitle {
                font-size: 1.2rem;
            }

            .features {
                flex-direction: column;
            }

            .feature {
                min-width: 100%;
            }

            .container {
                padding: 30px 20px;
            }
        }
    </style>
</head>
<body>
<!-- 背景动画 -->
<ul class="bg-bubbles">
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
</ul>

<div class="container">
    <div class="logo">💬</div>
    <h1>欢迎使用留言板</h1>
    <p class="subtitle">分享您的想法，倾听他人的声音</p>

    <div class="features">
        <div class="feature">
            <div class="feature-icon">✨</div>
            <div class="feature-title">简单易用</div>
            <div class="feature-desc">直观的界面设计，轻松发布和管理留言</div>
        </div>
        <div class="feature">
            <div class="feature-icon">🔒</div>
            <div class="feature-title">安全可靠</div>
            <div class="feature-desc">您的数据安全是我们的首要任务</div>
        </div>
        <div class="feature">
            <div class="feature-icon">🚀</div>
            <div class="feature-title">快速响应</div>
            <div class="feature-desc">优化的系统架构，提供流畅的使用体验</div>
        </div>
    </div>

    <a href="./message" class="cta-button">点击进入西大留言板</a>

    <div class="footer">
        <p>西南大学留言板系统 © 2024</p>
    </div>
</div>

<script>
    // 添加按钮点击效果
    document.querySelector('.cta-button').addEventListener('click', function(e) {
        // 创建涟漪效果
        let ripple = document.createElement('span');
        ripple.classList.add('ripple');
        this.appendChild(ripple);

        // 获取点击位置
        let rect = this.getBoundingClientRect();
        let x = e.clientX - rect.left;
        let y = e.clientY - rect.top;

        // 设置涟漪位置
        ripple.style.left = x + 'px';
        ripple.style.top = y + 'px';

        // 移除涟漪元素
        setTimeout(() => {
            ripple.remove();
        }, 600);
    });

    // 添加页面加载动画
    document.addEventListener('DOMContentLoaded', function() {
        const container = document.querySelector('.container');
        container.style.opacity = 0;
        container.style.transform = 'translateY(30px)';

        setTimeout(() => {
            container.style.transition = 'opacity 1s ease, transform 1s ease';
            container.style.opacity = 1;
            container.style.transform = 'translateY(0)';
        }, 300);
    });
</script>
</body>
</html>

